How can we get the overtime-values from the Personio API?

We like: https://yourdomain.personio.de/attendance/employee/1234567890/overtime-balance?period=2023-06

We want to proceed on this page to automate a process for the supervisors with their workers due to a existing company rule. How can we get the overtime-balance-values once at the start of a new month for the old month from Personio easily instead of all details for each calendar day by api - attendances?

Best regards